Use build time strings for pretty function names if supported.

This doesn't really do much until I have build time hashing.

src/CMakeLists.txt

@@ -1,8 +1,15 @@
 cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
 project(doorkeeper CXX C)
 
-include_directories(
-	.
+if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+	set(ID_IS_ORIGINAL_GNUC "1")
+else()
+	set(ID_IS_ORIGINAL_GNUC "0")
+endif()
+
+configure_file(
+	${PROJECT_NAME}_conf.h.in
+	${CMAKE_CURRENT_BINARY_DIR}/include/doorkeeper/implem/${PROJECT_NAME}_conf.h
 )
 
 add_library(${PROJECT_NAME}
@@ -11,3 +18,8 @@ add_library(${PROJECT_NAME}
 	tiger.c
 	hashing.cpp
 )
+
+target_include_directories(${PROJECT_NAME}
+	PRIVATE .
+	PUBLIC ${CMAKE_CURRENT_BINARY_DIR}/include
+)

src/doorkeeper_conf.h.in

@@ -0,0 +1,8 @@
+#ifndef idB523F14441E649E089C21CDE8189640C
+#define idB523F14441E649E089C21CDE8189640C
+
+#if @ID_IS_ORIGINAL_GNUC@ != 0
+#	define IS_ORIGINAL_GNUC
+#endif
+
+#endif